This invention relates to protective garments primarily for firefighters but which are also useful in industrial applications where workers may be exposed to very high heat flux. The garments, which include coats, jackets and/or pants, provide-protection against heat by reducing heat flow from the source to the body.
A great variety of garments which offer protection against heat are in use today. Most turnout gear commonly used by firefighters in the United States, comprise three layers, each performing a distinct function. There is an outer shell fabric often made from fiber of poly(m-phenylene isophthalamide) (MPD-I) and at times in combination with another heat and flame resistant fiber such as fiber from poly(p-phenylene terephthalamide) (PPD-T) or polybenzimidazole (PBI). Adjacent the outer shell is a moisture barrier. A laminate of Gore-Tex PTFE membrane with a fibrous nonwoven MPD-I/PPD-T substrate, or a laminate of Neoprene.RTM. with an MPD-I fibrous nonwoven is often employed for this purpose. Adjacent the moisture barrier, a thermal liner which generally comprises a batt of heat resistant fiber is used.
The outer shell serves to provide flame protection and serves as a primary defense. A thermal liner and a moisture barrier behind the outer shell offer comfort and protect against heat stress. The present invention focuses on a novel outer shell fabric which upon exposure to a high heat flux provides an additional significant margin of protection by changes in the garment fabric that reduce heat flow to the wearer.